Step 8: Stuff the Blaster

Step 9: Blast Away!

If all went well, you can begin felling stormtroopers.Here is a video of the blaster operating in a well lit room.

If you fancy a Star Wars rebel trooper blaster pistol, you have basically 2 commercial options. There is a blue plastic dart gun by Hasbro, or a great looking, solid but non-functional $400 model from Master Replicas. Neither of them shoot bolts of red light accross the room.

I wanted one that really "worked" and looked good, so I made my own. The project was more about learning electronics than anything else, but in addition to the new understanding of how to build blinky lights, I ended up with a pretty neat toy. I modeled mine after a Hero (that means it was used for close-ups) ROTJ Blaster prop that recently sold on ebay.

The blaster build consists of 2 sub-projects : building the electronic effects, and making the gun itself.

The circuitry is pretty basic and was my first real scratch-built electronic project. It involves a 555 IC timer circuit to trigger the sound and LED effects, and a 4017 decade counter chip to make the LED chaser effect seen at the rear of the gun.

The chassis of the blaster is made from PVC and aluminum tubing, some sheet aluminum a real scope and grip and a few other doodads.

Step 1: Electronic Effects Overview

When the trigger is pulled, the gun shoots out a pulse of bright red LED light out of the barrel, a pulse of laser from a laser diode, and a "blaster" sound is triggered. In addition, there is a line of 10 blue LED's that chase down the side of the gun creating some visual excitement.

In order to keep the effects synchronized and of a consistent duration, each trigger pull will set off a one-shot timer, which will trigger all of the effects for about 1/4 second, and then turn them off even if the trigger (switch) is held closed.

The Laser diode, Red LEDs (muzzle flash), and the sound effect module, and the blue LED chaser are all turned on by transistors that are triggered by the timer.

The LED chaser effect consists of another timer set up as a normal oscillator, which is driving a 4017 decade counter chip. The decade counter lights up each of the 10 LEDs in succession.

So, did you use just 4 AAA batteries = 6v supply or one 9v and 2 AA's with two seperate power supplies? Do the schematics reflect actual resistors and caps used on Your build? The directions show several so I am confused how it actually works. Please clarify.

I've been staring at these pictures for a couple days trying to make sense of it, but I've got no experience with electronics and timers, so I'm probably going to have to avoid circuits entirely and stick to push-button activation. Pulling the trigger would push the switch that completes the circuit, and it would remain on for as long as the trigger is held.

It would also be a nice idea to use the blue LEDs, instead of a chaser, to use them as a "round counter" to then just press a button to "reset" it. It's just something that came into mind while seeing how it works. Although it's really cool.

Thank you so much for the info on how you did your lighting effect -- I've been tinkering with a very similar idea (also tired of prop guns that make a wimpy sound and blink a single LED.) Nice to see the idea of combining a super-bright and a laser works so well. Can you share some info on the laser module and why you chose that particular one?

Oh, and there's enough on this page -- the assembly of the housing -- to warrant a full instructable on its own. You "expoxied aluminum skin to the cone?" Finding out more about how you did that, alone, would be worth the price of admission.

Very nice, but one thing I can't figure out is how you get the sound effect to play whenever you trigger it. I have the radio shack recordable module, but I can't figure out how to set it up so it will trigger when the power is switched on by the switch/trigger.

well, I honestly don't remember. But pin 3 is the output of the 555, so that should be wired to the base of the transistor. The collector is the positive, and the emitter is the negative side of the transistor, which you will wire up as the "switch" to activate the sound module. Sorry, I dont remember more specifics.

As far as making the sound play, mine just worked when triggered by the transistor. Maybe try removing the diode. Someone told me that I didnt realy need to use them. Although mine didn't work without them. And double-check the diode polarity.

the 555 one-shot triggers a transistor, which it wired to the "play button" on the sound module. pulling the trigger sets offf the 555 which turns on the transistors fro the various effects, one of which is the sound.

thank you for your reply, but how are the npn transistors (and the diodes) wired with the 555 one-shot? I'm having trouble looking at the images you have of the npn sequence to make out details on how it's wired. Is there a schematic you made?

Great project!!! I'd like to see about doing it myself, so I'm trying to lay out the entire circuit for all 3 functional blocks. I'm curious as to the final portion of the circuit, specifically the 3 chained NPNs. Can you post the outputs? Thanks.